From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 626EAC4741F for ; Mon, 9 Nov 2020 11:41:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 15934206ED for ; Mon, 9 Nov 2020 11:41:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604922074; bh=DdnMt4dQZoBazp+CcQ4voHqmXOu6LUFvv01/xOPmr+8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=XuE8Rke7YtS6+Gbd2sg/kS8tSOdy+F3yhOGv0O0+s4F51wShkpyfLFEtTrXuLUq/R +ushozfE51VwOlZ47OveqDijCPGA7YDPReUWMYuMj9c+ZmhH1ehxJNiLipofyuqszW QP48ENzCgIjTjeoaGUgrwj6Av/5yPl3gIEUll6Mg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729551AbgKILlM (ORCPT ); Mon, 9 Nov 2020 06:41:12 -0500 Received: from mail.kernel.org ([198.145.29.99]:33774 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729038AbgKILlM (ORCPT ); Mon, 9 Nov 2020 06:41:12 -0500 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 21A1F206ED; Mon, 9 Nov 2020 11:41:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604922071; bh=DdnMt4dQZoBazp+CcQ4voHqmXOu6LUFvv01/xOPmr+8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=UuFpOwJ3KiWu5V1sgJj/SVUK/BrOrRC1WZYcczQTEWqTTDT/EWgQ5lq73kVcI7Vid SMjjpP2945dgFy2GtvCM6LwPij2STkSf3vpKV4myivDKWiPrhJNtYrvjLXL1cEbEt9 EjeDNTJt9lJMvYdzjdccshE38LrC+uDoAvlfnX0Q= Date: Mon, 9 Nov 2020 12:42:11 +0100 From: Greg Kroah-Hartman To: Sudip Mukherjee Cc: Aisheng Dong , "Rafael J . Wysocki" , linux-kernel , Shawn Guo , Stephen Boyd Subject: Re: [PATCH RESEND] driver core: export device_is_bound() to fix build failure Message-ID: <20201109114211.GD1769924@kroah.com> References: <20201107224727.11015-1-sudipm.mukherjee@gmail.com> <20201108082317.GA40741@kroah.com> <20201109103703.GA1310551@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 09, 2020 at 11:18:56AM +0000, Sudip Mukherjee wrote: > Hi Aisheng, > > On Mon, Nov 9, 2020 at 10:57 AM Aisheng Dong wrote: > > > > Hi Greg, > > > > > From: Greg Kroah-Hartman > > > Sent: Monday, November 9, 2020 6:37 PM > > > Subject: Re: [PATCH RESEND] driver core: export device_is_bound() to fix build > > > failure > > > > > > On Mon, Nov 09, 2020 at 10:14:46AM +0000, Sudip Mukherjee wrote: > > > > Hi Greg, > > > > > > > > On Sun, Nov 8, 2020 at 8:23 AM Greg Kroah-Hartman > > > > wrote: > > > > > > > > > > On Sat, Nov 07, 2020 at 10:47:27PM +0000, Sudip Mukherjee wrote: > > > > > > When CONFIG_MXC_CLK_SCU is configured as 'm' the build fails as it > > > > > > is unable to find device_is_bound(). The error being: > > > > > > ERROR: modpost: "device_is_bound" [drivers/clk/imx/clk-imx-scu.ko] > > > > > > undefined! > > > > > > > > > > > > Export the symbol so that the module finds it. > > > > > > > > > > > > > > > probe() should never call this function as it makes no sense at all at that point in > > > time. The driver should be fixed. > > > > Would you suggest if any other API we can use to allow the driver to know whether > > another device has been probed? > > > > For imx scu driver in question, it has a special requirement that it depends on scu power domain > > driver. However, there're a huge number (200+) of power domains for each device clock, we can't define > > them all in DT for a single clock controller node. > > > > That's why we wanted to use device_is_bound() before to check if scu power domain is ready or not to > > support defer probe. > > iiuc, you are waiting for "fsl,scu-pd" to be registered. > I think you might be able to use bus_for_each_dev() to check if the > device has registered with the bus or not. It will be on the bus only > after bind was successful. The bus will be "platform_bus_type". No, do not do that, again, no individual driver should ever have to do that. Think about what would be involved if _every_ driver started doing this. > But I am sure Greg can give you better suggestion than this. :) device link :) thanks, greg k-h